If you can change some of the water daily (~25-50%) it should help, just allow for the Myxazin lost in the removed water.
Lets say you should be adding 3ml Myxazin per day to the tank...
- Day 1 add 3ml
- Day 2 50% water change, so 1.5ml Myxazin needs to be added back, then add further 3ml
- Day 3 50% water change, so 3ml Myxazin needs adding back, then add further 3ml
- etc. etc.